An outbreak of Listeria monocytogenes infections, which resulted in one death, was caused by contaminated home-delivered meals, according to the UK Health Security Agency (UKHSA).
In mid-April 2025, the Gastrointestinal Infections, Food Safety and One Health (GIFSOH) Division was informed of two cases of listeriosis with sample dates in March.
Sick people lived in the East Midlands and East of England. Both were male and the median age was 60, with one in the 50- to 59-year-old group and the other in the 60- to 69-year-old group.
Cases had underlying conditions and had been inpatients in the weeks before onset of symptoms but were hospitalized because of listeriosis. One person died, with Listeria monocytogenes infection listed as a cause of death on the death certificate.
Listeria monocytogenes isolates from patients were closely genetically related using whole genome sequencing (WGS), pointing to a common source of infection. Analysis of epidemiological data identified exposure to foods supplied by a company in London that delivers chef-prepared cook-chill meals to customers.
Both patients had eaten meals produced by the same company. One reported having prepacked cooked chicken and a sea-bass meal in February 2025, while the second case consumed teriyaki salmon, chili and garlic chicken donburi, lamb burger, potatoes and assorted vegetables shipped between February and March.
Inspection findings
Another case of listeriosis with a sample date in September 2024 had eaten food from the same business. However, it was not possible to determine by WGS if there was a match with the outbreak strain.
The Food Standards Agency (FSA) was informed, as was Havering Council, the local authority that oversaw this food firm. They met in May to discuss sampling, cleaning and halting production at the facility and again in July.
At the time of the investigation, the business had 22,000 customers across England, Wales, and Scotland. Havering Council was made aware in late 2024 and early 2025 of three alleged food poisoning complaints relating to the firm. Many meals are not RTE foods, they have been fully cooked, chilled and require thorough reheating before consumption.
In April 2025, Havering Council visited the company and found issues including condensation beneath the canopy, pools of stagnant water and damaged flooring. This led to three hygiene improvement notices between July and August and the food hygiene rating dropped from 4 to 1. The business contacted Campden BRI and the Chilled Food Association to ensure their Listeria management plan was aligned with industry best practice. By September, corrective actions had been completed. After a December inspection, a food hygiene rating of 4 was given.
The business voluntarily ceased production in May 2025, undertook a deep clean and re-opened a few days later following satisfactory results from in-house environmental testing and implementation of a Listeria management plan, including improving cleaning, partitioning of the facility and staff training. They also increased the concentration of cleaning chemicals on the recommendation of a hygiene consultant who visited the production facility.
Outbreak strain and other Listeria detected
A total of 109 samples, 73 environmental swabs and 36 from foods, were taken during several visits between April and October, including a parsley garnish. Listeria monocytogenes was found at low levels from food samples taken at the factory.
Listeria monocytogenes was detected during routine internal testing from two cold kitchen knives swabs taken by the business in mid-February 2024. There were also positives in end-of-shelf-life samples of chicken korma and hazelnut dukkah-crusted salmon meal in early March 2025, at levels of less than 20 colony forming units per gram (CFU/g). Food isolates were not kept by the private laboratory, so it is unknown if they were the outbreak strain.
Listeria matching the outbreak strain was found in one food and five environmental samples. The food isolate was from washed garnish parsley, sampled in May 2025, at less than 10 CFU/g. The five environmental isolates were from a cold kitchen drain gulley, a hot kitchen floor wall, dirty dollies, and two isolates from the hot kitchen floor/wall junction.
Local authority sampling found one food and four environmental Listeria isolates. The food isolate was from a chimichurri beef bowl at below 20 CFU/g.
In May, the business issued a product recall to its customer base for meals containing the garnish. A total of 110 customers received these meals. In June, the chimichurri beef bowl was recalled because of Listeria that did not match the outbreak strain.
Another 15 isolates of Listeria monocytogenes and 26 of other Listeria types were recovered from environmental samples taken between April and October 2025. The large number of positives at the facility suggested widespread and persistent contamination, according to UKHSA.
In January 2026, it was agreed that formal sampling would take place every two months over a 6-month period, beginning with an announced visit at the end of February by the local authority. No new cases in the cluster have since been identified.
